{"id":1276,"date":"2026-04-19T11:28:04","date_gmt":"2026-04-19T03:28:04","guid":{"rendered":"https:\/\/yunyanglib.cn\/?p=1276"},"modified":"2026-04-19T11:28:05","modified_gmt":"2026-04-19T03:28:05","slug":"%e3%80%90java%e3%80%91%e6%b7%b1%e5%ba%a6%e8%a7%a3%e6%9e%90%e4%b8%8d%e5%8f%af%e5%8f%98%e5%af%b9%e8%b1%a1%ef%bc%9a%e8%ae%be%e8%ae%a1%e5%8e%9f%e7%90%86%e3%80%81%e7%bb%8f%e5%85%b8%e6%a1%88%e4%be%8b","status":"publish","type":"post","link":"https:\/\/yunyanglib.cn\/?p=1276","title":{"rendered":"\u3010Java\u3011\u6df1\u5ea6\u89e3\u6790\u4e0d\u53ef\u53d8\u5bf9\u8c61\uff1a\u8bbe\u8ba1\u539f\u7406\u3001\u7ecf\u5178\u6848\u4f8b\u4e0e\u624b\u5199\u5b9e\u73b0"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u5927\u5bb6\u597d\uff0c\u6211\u662f\u4e91\u626c\uff5e \u4eca\u5929\u60f3\u548c\u5927\u5bb6\u6df1\u5165\u804a\u804a Java \u4e2d\u7684\u4e0d\u53ef\u53d8\u5bf9\u8c61 \u2014\u2014 \u8fd9\u4e2a\u770b\u4f3c\u57fa\u7840\u5374\u8574\u542b\u91cd\u8981\u8bbe\u8ba1\u601d\u60f3\u7684\u6982\u5ff5\uff0c\u4e0d\u4ec5\u5728\u65e5\u5e38\u5f00\u53d1\u4e2d\u9891\u7e41\u51fa\u73b0\uff08\u6bd4\u5982 String \u7c7b\uff09\uff0c\u66f4\u662f\u5e76\u53d1\u7f16\u7a0b\u3001\u7f13\u5b58\u8bbe\u8ba1\u4e2d\u7684\u5173\u952e\u6280\u672f\u9009\u578b\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e00\u3001\u4ec0\u4e48\u662f\u4e0d\u53ef\u53d8\u5bf9\u8c61\uff1f<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u5148\u660e\u786e\u6838\u5fc3\u5b9a\u4e49\uff1a<strong>\u4e00\u4e2a\u7c7b\u7684\u5bf9\u8c61\u5728\u901a\u8fc7\u6784\u9020\u65b9\u6cd5\u521b\u5efa\u540e\uff0c\u5176\u72b6\u6001\uff08\u6210\u5458\u53d8\u91cf\u503c\uff09\u65e0\u6cd5\u88ab\u540e\u7eed\u4fee\u6539\uff0c\u8fd9\u6837\u7684\u7c7b\u5c31\u662f\u4e0d\u53ef\u53d8\u7c7b<\/strong>\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e0d\u53ef\u53d8\u7c7b\u7684\u6838\u5fc3\u7279\u70b9\uff1a<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u6210\u5458\u53d8\u91cf\u4ec5\u5728\u6784\u9020\u65b9\u6cd5\u4e2d\u8d4b\u503c\uff0c\u65e0\u4efb\u4f55 setter \u65b9\u6cd5<\/li>\n\n\n\n<li>\u6bcf\u6b21 &#8220;\u4fee\u6539&#8221; \u5bf9\u8c61\u72b6\u6001\uff0c\u90fd\u4f1a\u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u5bf9\u8c61<\/li>\n\n\n\n<li>\u5929\u7136\u5177\u5907\u7ebf\u7a0b\u5b89\u5168\u6027\uff0c\u65e0\u9700\u989d\u5916\u540c\u6b65\u673a\u5236<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e8c\u3001\u4e3a\u4ec0\u4e48\u9700\u8981\u4e0d\u53ef\u53d8\u5bf9\u8c61\uff1f\u7ecf\u5178\u6848\u4f8b\u5206\u6790<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u6700\u5178\u578b\u7684\u4e0d\u53ef\u53d8\u7c7b\u5c31\u662f<code>String<\/code>\uff0c\u6211\u4eec\u5148\u4ece\u5b83\u7684\u8bbe\u8ba1\u601d\u8def\u5165\u624b\uff0c\u7406\u89e3\u4e0d\u53ef\u53d8\u5bf9\u8c61\u7684\u6838\u5fc3\u4ef7\u503c\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1. String \u7c7b\u7684\u4e0d\u53ef\u53d8\u6027\u8bbe\u8ba1<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5927\u5bb6\u6709\u6ca1\u6709\u60f3\u8fc7\uff0c\u4e3a\u4ec0\u4e48 String \u8981\u88ab\u8bbe\u8ba1\u6210\u4e0d\u53ef\u53d8\u7684\uff1f\u5176\u5b9e\u80cc\u540e\u6709\u4e09\u4e2a\u5173\u952e\u8003\u91cf\uff1a<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\uff081\uff09\u5b57\u7b26\u4e32\u5e38\u91cf\u6c60\u7684\u5e95\u5c42\u652f\u6491<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b57\u7b26\u4e32\u5e38\u91cf\u6c60\u662f JVM \u7684\u5185\u5b58\u4f18\u5316\u673a\u5236\uff0c\u5f53\u521b\u5efa\u5b57\u7b26\u4e32\u65f6\u4f1a\u4f18\u5148\u590d\u7528\u5e38\u91cf\u6c60\u4e2d\u5df2\u5b58\u5728\u7684\u5bf9\u8c61\u3002\u5982\u679c String \u662f\u53ef\u53d8\u7684\uff0c\u4fee\u6539\u4e00\u4e2a\u5bf9\u8c61\u4f1a\u5f71\u54cd\u6240\u6709\u5f15\u7528\u5b83\u7684\u5730\u65b9\uff0c\u5e38\u91cf\u6c60\u5c31\u5931\u53bb\u4e86\u5b58\u5728\u7684\u610f\u4e49\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ \u5e38\u91cf\u6c60\u590d\u7528\u793a\u4f8b\nString s1 = \"Java\";\nString s2 = \"Java\";\nSystem.out.println(s1 == s2); \/\/ true\uff0c\u6307\u5411\u540c\u4e00\u4e2a\u5e38\u91cf\u6c60\u5bf9\u8c61\nString s3 = new String(\"Java\");\nSystem.out.println(s1 == s3); \/\/ false\uff0cnew\u5173\u952e\u5b57\u5f3a\u5236\u521b\u5efa\u65b0\u5bf9\u8c61\n<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\">\uff082\uff09\u54c8\u5e0c\u503c\u7f13\u5b58\u63d0\u5347\u6548\u7387<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0d\u53ef\u53d8\u5bf9\u8c61\u7684 hashCode \u5728\u521b\u5efa\u65f6\u5c31\u88ab\u7f13\u5b58\uff0c\u540e\u7eed\u8c03\u7528\u4e0d\u4f1a\u91cd\u65b0\u8ba1\u7b97\u3002\u8fd9\u8ba9 String \u975e\u5e38\u9002\u5408\u4f5c\u4e3a HashMap\u3001HashSet \u7b49\u96c6\u5408\u7684\u952e\uff0c\u5927\u5e45\u63d0\u5347\u54c8\u5e0c\u8868\u7684\u67e5\u8be2\u6027\u80fd\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>String str = \"immutable\";\nint hash1 = str.hashCode();\nint hash2 = str.toLowerCase().hashCode(); \/\/ toLowerCase()\u8fd4\u56de\u65b0\u5bf9\u8c61\nint hash3 = str.hashCode(); \/\/ \u539f\u5bf9\u8c61hashCode\u4e0d\u53d8\nSystem.out.println(hash1 == hash3); \/\/ true\n<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\">\uff083\uff09\u7ebf\u7a0b\u5b89\u5168\u7684\u5929\u7136\u4fdd\u969c<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u591a\u7ebf\u7a0b\u73af\u5883\u4e0b\uff0c\u53ef\u53d8\u5bf9\u8c61\u7684\u72b6\u6001\u4fee\u6539\u53ef\u80fd\u5bfc\u81f4\u6570\u636e\u4e0d\u4e00\u81f4\u3002\u800c String \u7684\u4e0d\u53ef\u53d8\u6027\u8ba9\u5b83\u53ef\u4ee5\u5728\u591a\u4e2a\u7ebf\u7a0b\u95f4\u5b89\u5168\u5171\u4eab\uff0c\u65e0\u9700\u52a0\u9501\u540c\u6b65\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ \u591a\u7ebf\u7a0b\u5171\u4eabString\u793a\u4f8b\uff08\u65e0\u9700\u540c\u6b65\uff09\npublic class StringThreadSafeDemo {\n    private static final String SHARED_STR = \"\u5b89\u5168\u5171\u4eab\u7684\u5b57\u7b26\u4e32\";\n\n    public static void main(String&#91;] args) {\n        \/\/ \u7ebf\u7a0b1\u8bfb\u53d6\u5b57\u7b26\u4e32\n        new Thread(() -&gt; System.out.println(\"\u7ebf\u7a0b1\u8bfb\u53d6\uff1a\" + SHARED_STR)).start();\n        \/\/ \u7ebf\u7a0b2\u622a\u53d6\u5b57\u7b26\u4e32\uff08\u8fd4\u56de\u65b0\u5bf9\u8c61\uff0c\u4e0d\u5f71\u54cd\u539f\u5b57\u7b26\u4e32\uff09\n        new Thread(() -&gt; System.out.println(\"\u7ebf\u7a0b2\u5904\u7406\uff1a\" + SHARED_STR.substring(3))).start();\n    }\n}\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">2. \u5176\u4ed6\u5e38\u89c1\u4e0d\u53ef\u53d8\u7c7b<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u9664\u4e86 String\uff0cJava \u4e2d\u7684\u5305\u88c5\u5668\u7c7b\uff08Integer\u3001Long\u3001Double \u7b49\uff09\u4e5f\u90fd\u662f\u4e0d\u53ef\u53d8\u7c7b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ 1. \u521b\u5efa\u4e00\u4e2a Integer \u5bf9\u8c61\uff0c\u503c\u4e3a 100\uff0cnum1 \u5f15\u7528\u5b83\nInteger num1 = 100;\n\n\/\/ 2. num2 \u548c num1 \u6307\u5411\u3010\u540c\u4e00\u4e2a\u3011100 \u5bf9\u8c61\nInteger num2 = num1;\n\n\/\/ 3. \u5173\u952e\uff1a+= \u4e0d\u4f1a\u4fee\u6539\u539f\u5bf9\u8c61\uff0c\u800c\u662f\u521b\u5efa\u65b0\u5bf9\u8c61 105\n\/\/ num1 \u73b0\u5728\u6307\u5411\u65b0\u5bf9\u8c61\uff0cnum2 \u4f9d\u7136\u6307\u5411\u8001\u5bf9\u8c61\nnum1 += 5;\n\n\/\/ \u8f93\u51fa\u65b0\u5bf9\u8c61 105\nSystem.out.println(num1);\n\/\/ \u8f93\u51fa\u539f\u5bf9\u8c61 100\uff08\u539f\u5bf9\u8c61\u4ece\u672a\u88ab\u4fee\u6539\uff09\nSystem.out.println(num2);\n<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e09\u3001\u624b\u64b8\u4e00\u4e2a\u4e0d\u53ef\u53d8\u7c7b\uff1a\u56db\u6b65\u5b9e\u73b0<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e86\u89e3\u4e86\u539f\u7406\uff0c\u6211\u4eec\u6765\u4eb2\u624b\u5b9e\u73b0\u4e00\u4e2a\u4e0d\u53ef\u53d8\u7c7b\u3002\u8bb0\u4f4f\u6838\u5fc3\u56db\u8981\u7d20\uff1a<strong>\u7c7b final \u5316\u3001\u6210\u5458\u53d8\u91cf final \u5316\u3001\u65e0 setter\u3001\u4fee\u6539\u8fd4\u56de\u65b0\u5bf9\u8c61<\/strong>\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u5b9e\u73b0\u793a\u4f8b\uff1a\u4e0d\u53ef\u53d8\u7684 User \u7c7b<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ 1. \u7c7b\u58f0\u660e\u4e3afinal\uff0c\u7981\u6b62\u7ee7\u627f\npublic final class ImmutableUser {\n    \/\/ 2. \u6210\u5458\u53d8\u91cf\u58f0\u660e\u4e3afinal\uff0c\u4ec5\u5728\u6784\u9020\u65b9\u6cd5\u521d\u59cb\u5316\n    private final String username;\n    private final int age;\n    private final Address address; \/\/ \u5f15\u7528\u7c7b\u578b\u6210\u5458\n\n    \/\/ 3. \u6784\u9020\u65b9\u6cd5\u521d\u59cb\u5316\u6240\u6709\u6210\u5458\u53d8\u91cf\n    public ImmutableUser(String username, int age, Address address) {\n        this.username = username;\n        this.age = age;\n        \/\/ \u6ce8\u610f\uff1a\u5f15\u7528\u7c7b\u578b\u9700\u6df1\u62f7\u8d1d\uff0c\u907f\u514d\u5916\u90e8\u4fee\u6539\n        this.address = new Address(address.getProvince(), address.getCity());\n    }\n\n    \/\/ \u4ec5\u63d0\u4f9bgetter\u65b9\u6cd5\uff0c\u65e0setter\u65b9\u6cd5\n    public String getUsername() {\n        return username;\n    }\n\n    public int getAge() {\n        return age;\n    }\n\n    \/\/ \u5f15\u7528\u7c7b\u578b\u8fd4\u56de\u62f7\u8d1d\uff0c\u907f\u514d\u5916\u90e8\u4fee\u6539\n    public Address getAddress() {\n        return new Address(address.getProvince(), address.getCity());\n    }\n\n    \/\/ 4. \u4fee\u6539\u72b6\u6001\u65f6\u8fd4\u56de\u65b0\u5bf9\u8c61\n    public ImmutableUser updateAge(int newAge) {\n        return new ImmutableUser(this.username, newAge, this.address);\n    }\n\n    \/\/ \u8f85\u52a9\u7c7b\uff1a\u5730\u5740\u7c7b\uff08\u4e5f\u9700\u4fdd\u8bc1\u4e0d\u53ef\u53d8\uff09\n    public static final class Address {\n        private final String province;\n        private final String city;\n\n        public Address(String province, String city) {\n            this.province = province;\n            this.city = city;\n        }\n\n        public String getProvince() {\n            return province;\n        }\n\n        public String getCity() {\n            return city;\n        }\n    }\n}\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u6d4b\u8bd5\u4e0d\u53ef\u53d8\u6027<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>public class ImmutableTest {\n    public static void main(String&#91;] args) {\n        ImmutableUser.Address address = new ImmutableUser.Address(\"\u5b89\u5fbd\", \"\u5408\u80a5\");\n        ImmutableUser user1 = new ImmutableUser(\"\u4e91\u626c\", 28, address);\n        \n        \/\/ \u5c1d\u8bd5\"\u4fee\u6539\"\u7528\u6237\u4fe1\u606f\n        ImmutableUser user2 = user1.updateAge(29);\n        \/\/ \u539f\u5bf9\u8c61\u72b6\u6001\u4e0d\u53d8\n        System.out.println(user1.getAge()); \/\/ 28\n        \/\/ \u65b0\u5bf9\u8c61\u6301\u6709\u4fee\u6539\u540e\u72b6\u6001\n        System.out.println(user2.getAge()); \/\/ 29\n        \n        \/\/ \u9a8c\u8bc1\u5f15\u7528\u7c7b\u578b\u6210\u5458\u7684\u4e0d\u53ef\u53d8\u6027\n        ImmutableUser.Address address1 = user1.getAddress();\n        address1 = new ImmutableUser.Address(\"\u6c5f\u82cf\", \"\u5357\u4eac\"); \/\/ \u5916\u90e8\u4fee\u6539\u4e0d\u5f71\u54cd\u539f\u5bf9\u8c61\n        System.out.println(user1.getAddress().getProvince()); \/\/ \u5b89\u5fbd\uff08\u539f\u5bf9\u8c61\u5730\u5740\u672a\u53d8\uff09\n    }\n}\n<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">\u56db\u3001\u5c0f\u7ed3<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0d\u53ef\u53d8\u5bf9\u8c61\u7684\u8bbe\u8ba1\u601d\u60f3\u6838\u5fc3\u662f &#8220;\u72b6\u6001\u4e0d\u53ef\u53d8\uff0c\u4fee\u6539\u521b\u5efa\u65b0\u5bf9\u8c61&#8221;\uff0c\u5176\u4f18\u52bf\u5728\u4e8e\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u7ebf\u7a0b\u5b89\u5168\uff0c\u65e0\u9700\u540c\u6b65<\/li>\n\n\n\n<li>\u54c8\u5e0c\u503c\u7f13\u5b58\uff0c\u63d0\u5347\u96c6\u5408\u6027\u80fd<\/li>\n\n\n\n<li>\u652f\u6301\u5e38\u91cf\u6c60\u590d\u7528\uff0c\u8282\u7701\u5185\u5b58<\/li>\n\n\n\n<li>\u51cf\u5c11\u5e76\u53d1 bug\uff0c\u4ee3\u7801\u66f4\u53ef\u9760<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u9664\u4e86\u6211\u4eec\u624b\u5199\u7684\u793a\u4f8b\uff0cString\u3001\u5305\u88c5\u5668\u7c7b\u8fd9\u4e9b JDK \u5185\u7f6e\u7684\u4e0d\u53ef\u53d8\u7c7b\uff0c\u5728\u5f00\u53d1\u4e2d\u4e00\u5b9a\u8981\u6ce8\u610f\u5b83\u4eec\u7684 &#8220;\u4e0d\u53ef\u53d8\u7279\u6027&#8221;\u2014\u2014 \u907f\u514d\u8bef\u4ee5\u4e3a\u8c03\u7528\u65b9\u6cd5\u4f1a\u4fee\u6539\u539f\u5bf9\u8c61\uff0c\u800c\u662f\u8981\u63a5\u6536\u65b9\u6cd5\u8fd4\u56de\u7684\u65b0\u5bf9\u8c61\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u5927\u5bb6\u5728\u5b9e\u9645\u5f00\u53d1\u4e2d\u9047\u5230\u4e0d\u53ef\u53d8\u5bf9\u8c61\u7684\u5e94\u7528\u573a\u666f\uff0c\u6216\u8005\u6709\u76f8\u5173\u7591\u95ee\uff0c\u6b22\u8fce\u5728\u8bc4\u8bba\u533a\u4ea4\u6d41\uff5e \u540e\u7eed\u6211\u8fd8\u4f1a\u5206\u4eab\u66f4\u591a Java \u6838\u5fc3\u77e5\u8bc6\u70b9\uff0c\u8bb0\u5f97\u5173\u6ce8\u54e6\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5927\u5bb6\u597d\uff0c\u6211\u662f\u4e91\u626c\uff5e \u4eca\u5929\u60f3\u548c\u5927\u5bb6\u6df1\u5165\u804a\u804a Java \u4e2d\u7684\u4e0d\u53ef\u53d8\u5bf9\u8c61 \u2014\u2014 \u8fd9\u4e2a\u770b\u4f3c\u57fa\u7840\u5374\u8574\u542b\u91cd\u8981\u8bbe\u8ba1\u601d\u60f3\u7684\u6982\u5ff5<\/p>\n<div class=\"more-link\">\n\t\t\t\t <a href=\"https:\/\/yunyanglib.cn\/?p=1276\" class=\"link-btn theme-btn\"><span>Read More <\/span> <i class=\"fa fa-caret-right\"><\/i><\/a>\n\t\t\t<\/div>\n","protected":false},"author":1,"featured_media":1280,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20],"tags":[15],"class_list":["post-1276","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-java","tag-java"],"_links":{"self":[{"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/posts\/1276","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1276"}],"version-history":[{"count":3,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/posts\/1276\/revisions"}],"predecessor-version":[{"id":1279,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/posts\/1276\/revisions\/1279"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/media\/1280"}],"wp:attachment":[{"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1276"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1276"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1276"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}